Download COMMON SUBSTANCES ESSENTIAL TO LIVING THINGS

COMMON SUBSTANCES
ESSENTIAL TO LIVING THINGS
Lesson Objective: Students will identify common
organic and inorganic substances that are
essential to living things.
REVIEW:
¢  Fossil
fuels are also known as?
¢ Why?
¢ Ever
wonder
what you are
made of?
ACTUALLY…
¢  The
composition of the human body is:
¢  Water, proteins, fats, sugars, starch, DNA,
minerals, vitamins, salts, acids, and bases.
OUR BODIES NEED ABOUT 25 ELEMENTS
FOR NORMAL GROWTH (PAGE 197).
Carbon(C), oxygen(O) &
hydrogen(H) are the most
common elements found in living
things.
¢ They
make up complex
molecules that form sugar,
starch, fat, oil, wax, and
proteins.
ORGANIC COMPOUNDS
¢ Because
these complex
molecules contain carbon, they
are called organic compounds.
¢  Atomic
Number: Shows how many protons are in
the nucleus.
¢  Atomic Weight (Mass): The total mass of all the
protons and neutrons in an atom.
¢  Electrons: so tiny they have very little effect on
the mass of an atom.
INORGANIC COMPOUNDS
¢ Substances
that do not contain
carbon are called inorganic
compounds.
INORGANIC EXAMPLES:
ON EARTH, THERE ARE WAY MORE
ORGANIC MOLECULES THAN INORGANIC!
NUTRIENTS
¢ Nutrients
are elements and
compounds needed for living,
growing, and reproducing.
¢ Plants
get nutrients they need from
the air and water (carbon, hydrogen,
oxygen), and from the soil (nitrogen,
phosphorus, potassium, magnesium,
calcium, sulfur).
ANIMALS GET NUTRIENTS FROM?
MACRONUTRIENTS
¢  Macro
means large or large-scale
MICRONUTRIENTS
¢  Micro
means very small or small-scale.
6 ELEMENTS MAKE UP 99% OF
THE HUMAN BODY
¢ Oxygen,
carbon, hydrogen, nitrogen,
calcium & phosphorus.
MAINTAINING THE RIGHT LEVEL
OF NUTRIENTS
¢  Consider
a farmer who notices that crops are not
growing well; lower leaves of plants show distinct
yellow striping, and plants are not as tall as they
should be:
¢ The
farmer has been applying
nitrogen, phosphorus &
potassium…
¢ To
the soil expecting to get high
yields from the crops.
BUT…
¢  Soil
tests show low levels of magnesium & high
levels of potassium. Farmers know high levels of
potassium can interfere with absorption of
magnesium by the plant.
¢ One
solution: stop applying fertilizer
with potassium and apply a fertilizer
containing magnesium.
¢ Same
with humans… Protein is
good, but…
OPTIMUM AMOUNTS:
¢  Reservoir
built in California in 1980 to control
the flow of irrigation water to farms.
SHORTLY AFTER IT WAS BUILT:
¢ Fish
in the reservoir died.
¢ Birds
living on or near reservoir
died/dying; produced abnormal
chicks.
¢ Tests
showed surviving fish and
birds contained a high level of
selenium.
¢ Selenium
was traced back to soil in
and around reservoir.
MICRONUTRIENT SELENIUM IS AN ELEMENT
THAT IS REQUIRED IN TRACE AMOUNTS
¢  Too
much or too little can cause harmful health
effects.
IF PLANTS HAVE TOO LITTLE SELENIUM,
ANIMALS THAT EAT THEM WILL ALSO BE
DEFICIENT IN SELENIUM
¢  Studies:
selenium deficiency in humans can be
linked to cancer and heart disease.
¢  Selenium, along with vitamin E, helps protect
cell membranes from damage caused by hydrogen
peroxide, a poison that is produced by some
chemical reactions in cells.
OPTIMUM AMOUNTS:
¢ The
amount of a substance/nutrient
that provides an organism with the
best health.
¢  For
humans, at least 70 ug (micrograms) of
selenium per day is recommended.
TYPES OF ORGANIC
MOLECULES:
¢ Four
important classes of
organic compounds…
¢ Carbohydrates
¢ Lipids
¢ Proteins
¢ Nucleic Acids
CARBOHYDRATES:
¢  Are
organic molecules made up of atoms of
carbon, hydrogen, and oxygen.
¢  These
atoms can form simple molecules, such as
sugar, or large, complex molecules, such as
starch, cellulose, and glycogen.
GLUCOSE IS THE SIMPLE SUGAR MADE BY
GREEN PLANTS IN PHOTOSYNTHESIS.
¢  The
atoms in a molecule of glucose usually join
together to form a 6 sided figure: C6H12O6
COMPLEX CARBOHYDRATES
¢  Such
as cellulose, starch, and glycogen are
composed of many molecules joined together:
LIPIDS:
¢  Are
compounds composed of many carbon,
hydrogen, and oxygen atoms.
BOTH ANIMALS & PLANTS
PRODUCE LIPIDS
¢  Our
skin produces oils, and our bodies store food
in the form of fat.
¢  Plant
products such as canola seeds, corn,
peanuts, soybeans, walnuts, and cashews contain
large amounts of oils.
FAT MOLECULE: MADE UP OF 3 CHAINS OF
FATTY ACIDS CONNECTED TO 1 MOLECULE OF A
COMPOUND CALLED GLYCEROL.
PROTEINS AND AMINO ACIDS:
PROTEINS:
¢ Have
many functions.
¢ Used by organisms for growth,
repair, and as a source of energy.
PROTEINS:
¢  Are
the main component of enzymes.
¢  Remember that enzymes are catalysts
that control chemical reactions in
organisms
PROTEINS ARE ORGANIC COMPOUNDS THAT
ARE MADE UP OF AMINO ACIDS
¢  The
way amino acids form proteins is similar to
the way glucose units join together to form
complex carbohydrates such as starch.
EACH PROTEIN HAS ITS OWN NUMBER AND
ARRANGEMENT OF AMINO ACIDS.
¢  Usually,
a protein contains between 40 and 500
amino acid units.
¢  Insulin
(which regulates carbohydrate and fat
metabolism in the body- diabetes) contains 51
amino acid units arranged as two chains.
¢  20
different kinds of amino acids are common in
proteins.
¢  Green
plants convert glucose into amino acids.
NUCLEIC ACIDS
¢  Are
the largest and most complicated molecules
found in living things.
¢ All
cells contain two
important nucleic acids- DNA
(deoxyribonucleic acid) &
RNA (ribonucleic acid).
DNA AND RNA ARE MADE UP OF 3
SUBSTANCES:
¢ Phosphates
¢ 
A simple sugar called ribose
¢ Nitrogen-containing
molecules.
¢ Nucleic
acids play a major role
in heredity and in controlling a
cell’s activities.
¢  DNA
transfers information about an organism’s
body from one generation to the next.
¢  RNA
transmits genetic information from DNA to
proteins produced by the cell.
CHECK & REFLECT
¢ Page
203, #s 1-7, Due
Wednesday, Jan 13.